JP2010216578A - Dynamic damper and propeller shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the drawing resistance of a rubber layer press-fitted to a hollow shaft to the hollow shaft in a dynamic damper having the rubber layer on the outer periphery. <P>SOLUTION: This dynamic damper 10 includes an outer pipe 20, a weight 30 disposed in the outer pipe 20, an elastic body 40 interposed between the outer pipe 20 and the weight 30, and a rubber layer 50 put on the outer peripheral surface of the outer pipe 20. A rubber compression means 60 is provided to both ends of the rubber layer 50. The rubber compression means 60 raises the compression ratio of both ends of the rubber layer 50 more than that of the other portions of the rubber layer 50 when the dynamic damper 10 is press-fitted into the hollow shaft 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dynamic damper and a propeller shaft.

  As described in Patent Document 1, an outer pipe and an inner part of an outer pipe are used as a dynamic damper that is pressed into a straight circular hole in the axial direction of a hollow propeller shaft to reduce vibration of the propeller shaft and reduce vehicle body vibration and noise. And a rubber layer that is attached to the outer peripheral surface of the outer pipe, and an elastic body interposed between the outer pipe and the weight.

  The dynamic damper can be easily inserted into the hole of the hollow shaft by elastic deformation of the rubber layer, and can be fixed by being pressed into the hole by the elastic force of the rubber layer.

JP 3-288041 A

  In the dynamic damper described in Patent Document 1, a rubber layer press-fitted into a hole of a hollow propeller shaft is formed into a straight cylindrical shape in the axial direction, and an outer pipe to which the rubber layer is attached is formed into a straight cylindrical shape in the axial direction. Yes. Therefore, the pressed rubber layer is affected by press-fitting load, heat, vibration, etc., and both end portions released to the outside of the rubber layer are from the annular gap between the hollow propeller shaft and the outer pipe. Escape and deform as if on the side of the. As a result, the pressure contact force of the rubber layer with respect to the hollow propeller shaft is reduced at both ends of the rubber layer, and there is a possibility that the resistance of the rubber layer against the hollow propeller shaft will fall off.

  SUMMARY OF THE INVENTION An object of the present invention is to improve durability of a rubber layer press-fitted into a hollow shaft to the hollow shaft in a dynamic damper in which a rubber layer is provided on the outer periphery of the outer pipe, thereby ensuring durability and reliability.

  The invention according to claim 1 includes an outer pipe, a weight disposed inside the outer pipe, an elastic body interposed between the outer pipe and the weight, and a rubber layer attached to the outer peripheral surface of the outer pipe. In the dynamic damper, the rubber compressing means is provided at both ends of the rubber layer, and the rubber compressing means determines the compressibility of the both ends of the rubber layer when the dynamic damper is press-fitted into the hollow shaft. The compression rate is higher than that.

  According to a second aspect of the present invention, in the first aspect of the invention, the rubber compression means further expands the outer peripheral surface of the outer pipe to which the rubber layer is attached at both ends of the outer pipe toward the outer side in the axial direction. It consists of an enlarged diameter part.

  According to a third aspect of the present invention, in the first aspect of the present invention, the rubber compressing means may further comprise protrusions in which the outer diameters of both end portions of the rubber layer are protruded from the outer diameters of other portions of the rubber layer. It is a thing.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the rubber compression means further expands the outer peripheral surface of the outer pipe to which the rubber layer is attached at one end of the outer pipe toward the outer side in the axial direction. The outer diameter of the rubber layer located on the side of the other end of the outer pipe is made of a protrusion that protrudes from the outer diameter of the other part of the rubber layer. is there.

  The invention according to claim 5 is a propeller shaft in which the dynamic damper according to any one of claims 1 to 4 is press-fitted into a hollow shaft and fixedly arranged.

(Claim 1)
(a) Rubber compression means is provided at both ends of the rubber layer constituting the dynamic damper, and the rubber compression means determines the compression rate of both ends of the rubber layer when the dynamic damper is pressed into the hollow shaft. It is assumed that the compression rate is higher than other parts. Therefore, even if the press-fitted rubber layer is affected by press-fitting load, heat, etc., the compressibility of both ends released to the outside of the rubber layer is set high in advance. Even if the portion escapes from the annular gap between the hollow shaft and the outer pipe so as to cover the both end surfaces of the outer pipe, it is possible to suppress a decrease in the pressure contact force at both ends. As a result, the pressure of the rubber layer against the hollow shaft does not decrease over the entire length including both ends of the rubber layer. The resistance to slipping of the rubber layer with respect to the hollow shaft can be improved.

  (b) Since the rubber compression means is provided at both ends of the rubber layer, the rubber layer is improved in resistance to slipping out of the hollow shaft as compared with the rubber compression means provided only at one end of the rubber layer. Therefore, the concentricity of the dynamic damper can be stably maintained, the vibration of the hollow shaft can be reduced efficiently, and the vibration and noise of the vehicle body can be reduced.

(Claim 2)
(c) The rubber compression means is composed of enlarged diameter portions at both ends of the outer pipe. At this time, the outer diameter of the rubber layer is assumed to be straight in the axial direction. Therefore, the initial thickness t before press-fitting the rubber layer is smaller than the other parts at both ends, and the compression amount Δt due to press-fitting of the rubber layer is the same (substantially constant) at both ends and the other parts. The compression rate Δt / t increases at both ends.

(Claim 3)
(d) The rubber compression means is composed of protrusions having outer diameters at both ends of the rubber layer. At this time, the outer peripheral diameter of the outer pipe is straight in the axial direction. Therefore, by setting the projection amount (≈compression amount) of the outer diameter projections at both ends of the rubber layer to be large, the compression rate of the rubber layer increases at both ends.

(Claim 4)
(e) The rubber compression means is composed of an enlarged diameter portion at one end portion of the outer pipe and a protrusion portion having an outer diameter at the other end portion of the rubber layer located on the other end portion side of the outer pipe. As a result, the compression rate of the rubber layer is increased by the aforementioned (c) on the one end portion side of the outer pipe, and the compression rate of the rubber layer is increased by the aforementioned (d) on the other end portion side of the outer pipe. Providing the protrusion portion having the outer diameter of the rubber layer only at one end portion of the rubber layer prevents the protrusion portion from being undercut in the die cutting portion of the dynamic damper with respect to the molding die, thereby improving the die releasing property of the dynamic damper.

(Claim 5)
(f) In the propeller shaft, the above (a) to (e) can be realized.

1A and 1B show a dynamic damper according to a first embodiment, where FIG. 1A is a front view and FIG. 1B is a cross-sectional view taken along line BB. 2A and 2B show a dynamic damper according to a second embodiment, in which FIG. 2A is a front view and FIG. 2B is a cross-sectional view taken along line BB. 3A and 3B show a dynamic damper according to a third embodiment, in which FIG. 3A is a front view and FIG. 3B is a cross-sectional view taken along line BB.

Example 1
The dynamic damper 10 of FIG. 1 is press-fitted into a predetermined position in the axial direction in a circular hole straight in the axial direction of the hollow shaft 2 of the propeller shaft 1 for an automobile, and is fixedly arranged. The dynamic damper 10 reduces the vibration of the propeller shaft 1 and reduces vehicle body vibration and noise.

  The dynamic damper 10 includes an outer pipe 20, a weight 30, an elastic body 40, and a rubber layer 50.

  The outer pipe 20 has a cylindrical shape as described later, and is formed of a wound pipe made of a metal plate such as a spring steel plate or a hollow pipe of a metal tube such as a steel pipe.

  The weight 30 has a short column shape such as a cylinder and is made of a metal bar such as a steel bar. The weight 30 is disposed concentrically with the outer pipe 20 inside the outer pipe 20. The weight 30 is wider than the outer pipe 20.

  The elastic body 40 is disposed in the annular space 11 between the outer pipe 20 and the weight 30, an outer peripheral layer 41 bonded to the inner surface of the outer pipe 20, an inner peripheral layer 42 bonded to the outer surface of the weight 30, and an outer peripheral layer 41 and an elastic interposing portion 43 provided at a plurality of circumferential positions (5 positions in the present embodiment) between the inner circumferential layer 42 and the inner circumferential layer 42. The outer peripheral layer 41 and the inner peripheral layer 42 have substantially the same width as the outer pipe 20. The elastic interposing portion 43 is narrower than the outer peripheral layer 41 and the inner peripheral layer 42 and is erected at the center in the width direction of the outer peripheral layer 41 and the inner peripheral layer 42. The elastic body 40 is provided with a penetrating cavity 44 between adjacent elastic intervention parts 43, 43. The elastic body 40 is made of synthetic rubber or the like, and is integrally vulcanized with the outer pipe 20 and the weight 30.

  The rubber layer 50 is attached to the outer peripheral surface of the outer pipe 20. The rubber layer 50 has an outer diameter that is straight in the axial direction, has a cylindrical shape having an outer diameter larger than the hole diameter of the hollow shaft 2, and is inserted into the hole of the hollow shaft 2 by being press-fitted into the dynamic damper 10. Is fixed at a predetermined position in the axial direction by the elastic force and friction of the rubber layer 50 against the hole of the hollow shaft 2.

  However, the dynamic damper 10 is provided with rubber compression means 60 at both ends of the rubber layer 50. When the dynamic damper 10 is press-fitted into the hole of the hollow shaft 2, the rubber compression means 60 determines the compression rate at both ends of the rubber layer 50 to other portions of the rubber layer 50 (intermediate portions sandwiched between both ends). It will be higher than the compression ratio.

  The rubber compressing means 60 of the present embodiment is composed of an enlarged diameter portion 70 in which the outer peripheral surface of the outer pipe 20 to which the rubber layer 50 is attached is expanded toward the outside in the axial direction at both ends of the outer pipe 20. It is. In addition, the intermediate part pinched | interposed into the enlarged diameter part 70 of the both ends of the outer pipe 20 shall be a straight cylindrical shape in the axial direction. Both end portions of the outer pipe 20 have a cylindrical shape that expands in a tapered shape from the straight cylindrical intermediate portion of the outer pipe 20 toward the outside in the axial direction. Since the outer diameter of the rubber layer 50 attached to the outer peripheral surface of the outer pipe 20 is straight in the axial direction, the initial thickness t of the rubber layer 50 before press-fitting into the hole of the hollow shaft 2 is the both ends. The part becomes smaller in the direction toward the end part than the other part. When the dynamic damper 10 is inserted into the hole of the hollow shaft 2, the rubber layer 50 is elastically compressed in the hole of the hollow shaft 2 at both ends and the middle part.

  The dynamic damper 10 is vulcanized by injecting rubber and integrally forming the elastic body 40 and the rubber layer 50 in a state where the outer pipe 20 and the weight 30 are disposed in the mold.

Therefore, according to the dynamic damper 10 of the present embodiment, the following operational effects can be obtained.
(a) Rubber compression means 60 is provided at both ends of the rubber layer 50 constituting the dynamic damper 10, and the rubber compression means 60 is provided at both ends of the rubber layer 50 when the dynamic damper 10 is pressed into the hollow shaft 2. It is assumed that the compression rate is higher than the compression rate of other portions of the rubber layer 50. Therefore, even when the press-fitted rubber layer 50 is affected by press-fitting load, heat, vibration, etc., the compression ratios at both ends released to the outside of the rubber layer 50 are set high in advance. Escape deformation can be prevented so that both end portions of the rubber layer 50 are covered from the annular gap between the hollow shaft 2 and the outer pipe 20 toward the both end surface sides of the outer pipe 20, and a decrease in pressure contact force at both end portions can be prevented. As a result, the pressing force of the rubber layer 50 against the hollow shaft 2 does not decrease over the entire length including both ends of the rubber layer 50, and large acceleration and vibration due to a sudden change in torque due to the rotation of the hollow shaft 2 are caused. Even if it occurs, the slipping resistance of the rubber layer 50 to the hollow shaft 2 can be improved.

  (b) Since the rubber compression means 60 is provided at both ends of the rubber layer 50, the rubber layer 50 is more resistant to the hollow shaft 2 than the rubber compression means 60 provided only at one end of the rubber layer 50. While improving, the concentricity of the dynamic damper 10 with respect to the hollow shaft 2 can also be maintained stably, the vibration of the hollow shaft 2 can be efficiently reduced, and vehicle body vibration and noise can be reduced.

  (c) The rubber compression means 60 is composed of the enlarged diameter portions 70 at both ends of the outer pipe 20. At this time, the outer diameter of the rubber layer 50 is assumed to be straight in the axial direction. Therefore, the initial thickness t before press-fitting the rubber layer 50 is smaller than the other parts at both ends, and the compression amount Δt due to press-fitting of the rubber layer 50 is the same at both ends and other parts. The compression rate Δt / t increases at both ends.

  (d) In the propeller shaft 1, the above-described (a) to (c) can be realized.

  In the dynamic damper 10, both ends of the outer pipe 20 are formed in a cylindrical shape that expands in a tapered shape, and the diameter-expanded portions 70 at both ends of the outer pipe 20 are continuous in the circumferential direction of the outer pipe 20. However, the enlarged diameter portions 70 at both ends of the outer pipe 20 may be provided at a plurality of locations at equal intervals in the circumferential direction of the outer pipe 20.

(Example 2)
The dynamic damper 100 shown in FIG. 2 is substantially different from the dynamic damper 10 shown in FIG. In the dynamic damper 100, the outer pipe 20 has a cylindrical shape having a straight inner and outer diameter in the axial direction.

  The rubber compressing means 60 of the present embodiment is composed of protrusions 80 in which the outer diameters of both end portions of the rubber layer 50 are protruded from the outer diameters of the other portions of the rubber layer 50. When the dynamic damper 100 is inserted into the hole of the hollow shaft 2, the rubber layer 50 has the protrusions 80 at both ends and the entire intermediate part sandwiched between the protrusions 80 at both ends within the hole of the hollow shaft 2. Compressed elastically. The protrusion 80 of the present embodiment has an annular shape that is continuous in the circumferential direction of the rubber layer 50.

  The dynamic damper 100 is vulcanized by injecting rubber and integrally forming the elastic body 40 and the rubber layer 50 in a state where the outer pipe 20 and the weight 30 are disposed in the mold.

According to the dynamic damper 100 of the present embodiment, the following operational effects can be obtained.
(a) Rubber compression means 60 is provided at both ends of the rubber layer 50 constituting the dynamic damper 100, and the rubber compression means 60 is provided at both ends of the rubber layer 50 when the dynamic damper 100 is press-fitted into the hollow shaft 2. It is assumed that the compression rate is higher than the compression rate of other portions of the rubber layer 50. Therefore, even when the press-fitted rubber layer 50 is affected by press-fitting load, heat, vibration, etc., the compression ratios at both ends released to the outside of the rubber layer 50 are set high in advance. Escape deformation is suppressed so that both end portions of the rubber layer 50 are covered from the annular gap between the hollow shaft 2 and the outer pipe 20 toward the both end surfaces of the outer pipe 20, and as a result, the pressure contact force is not reduced. As a result, the pressing force of the rubber layer 50 against the hollow shaft 2 does not decrease over the entire length including both ends of the rubber layer 50, and large acceleration and vibration due to the rotational speed of the hollow shaft 2, a sudden change in torque, etc. Even if it occurs, the slipping resistance of the rubber layer 50 to the hollow shaft 2 can be improved.

  (b) Since the rubber compression means 60 is provided at both ends of the rubber layer 50, the rubber layer 50 is more resistant to the hollow shaft 2 than the rubber compression means 60 provided only at one end of the rubber layer 50. While improving, the concentricity of the dynamic damper 100 with respect to the hollow shaft 2 can also be stably maintained, vibration of the hollow shaft 2 can be further reduced, and vehicle body vibration and noise can be reduced.

  (c) It is assumed that the rubber compression means 60 is composed of protrusions 80 having outer diameters at both ends of the rubber layer 50. At this time, the outer peripheral diameter of the outer pipe 20 is assumed to be straight in the axial direction. Therefore, by setting the protrusion amount (≈compression amount) of the protrusion portions 80 having outer diameters at both ends of the rubber layer 50, the compression rate of the rubber layer 50 increases at both ends.

  (d) In the propeller shaft 1, the above-described (a) to (c) can be realized.

  In the dynamic damper 100, the protrusions 80 at both ends of the rubber layer 50 are continuous in the circumferential direction of the rubber layer 50. However, the protrusions 80 at both ends of the rubber layer 50 may be provided at a plurality of locations at equal intervals in the circumferential direction of the rubber layer 50.

Example 3
The dynamic damper 200 shown in FIG. 3 is substantially different from the dynamic damper 10 shown in FIG.

  The rubber compression means 60 of the present embodiment includes a diameter-expanded portion 70 having an outer peripheral surface of the outer pipe 20 to which the rubber layer 50 is attached at one end portion of the outer pipe 20, and the diameter of the outer pipe 20 is increased outward in the axial direction. The outer pipe 20 includes a protrusion 80 in which the outer diameter of the other end portion of the rubber layer 50 located on the other end portion side is protruded from the outer diameter of the other portion of the rubber layer 50. That is, in the dynamic damper 200, the one end side half of the dynamic damper 200 has the same enlarged diameter portion 70 as the one end side half of the dynamic damper 10 in FIG. The portion has a protrusion 80 similar to the other half of the other end of the dynamic damper 100 of FIG.

  The dynamic damper 200 is vulcanized by injecting rubber and integrally forming the elastic body 40 and the rubber layer 50 in a state where the outer pipe 20 and the weight 30 are disposed in the mold.

According to the dynamic damper 200 of the present embodiment, the following operational effects can be obtained.
(a) Rubber compression means 60 is provided at both ends of the rubber layer 50 constituting the dynamic damper 200, and the rubber compression means 60 is provided at both ends of the rubber layer 50 when the dynamic damper 200 is press-fitted into the hollow shaft 2. It is assumed that the compression rate is higher than the compression rate of other portions of the rubber layer 50. Therefore, even when the press-fitted rubber layer 50 is affected by a press-fit load, heat, or the like, the compressibility at both ends released to the outside of the rubber layer 50 is set high in advance. As the both end portions of 50 are covered from the annular gap between the hollow shaft 2 and the outer pipe 20 toward the both end surfaces of the outer pipe 20, the escape deformation is suppressed and the pressure contact force does not decrease. As a result, the pressure contact force of the rubber layer 50 against the hollow shaft 2 does not decrease over the entire length including both ends of the rubber layer 50, and large acceleration and vibration due to the rotational speed of the hollow shaft 2, a sudden change in torque, etc. Even if it occurs, the slipping resistance of the rubber layer 50 to the hollow shaft 2 can be improved.

  (b) Since the rubber compression means 60 is provided at both ends of the rubber layer 50, the rubber layer 50 is more resistant to the hollow shaft 2 than the rubber compression means 60 provided only at one end of the rubber layer 50. While improving, the concentricity of the dynamic damper 200 with respect to the hollow shaft 2 can also be stably maintained, the vibration of the hollow shaft 2 can be efficiently reduced, and the vehicle body vibration and noise can be reduced.

  (c) The rubber compressing means 60 is composed of a diameter-expanded portion 70 at one end of the outer pipe 20 and a protrusion 80 having an outer diameter at the other end of the rubber layer 50 located on the other end side of the outer pipe 20. . As a result, the compression rate of the rubber layer 50 is increased in the same manner as the above-described enlarged diameter portion 70 of the dynamic damper 10 on the one end portion side of the outer pipe 20, and the compression rate of the rubber layer 50 is increased on the other end portion side of the outer pipe 20. According to the protrusion 80 of the dynamic damper 100 described above, it is raised in the same manner. By providing the protruding portion 80 having the outer diameter of the rubber layer 50 only at one end portion of the rubber layer 50, the protruding portion 80 is not undercut at the die cutting portion of the dynamic damper 200 with respect to the mold, and the mold of the dynamic damper 200 The punchability can be improved.

  (d) In the propeller shaft 1, the above-described (a) to (c) can be realized.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

  The present invention provides rubber compressing means at both ends of the rubber layer, and the rubber compressing means determines the compressibility of the rubber layer at both ends when the dynamic damper is press-fitted into the hollow shaft. By making it higher than the compression rate, in a dynamic damper having a rubber layer on the outer periphery, it is possible to improve the resistance of the rubber layer press-fitted into the hollow shaft to the hollow shaft.

DESCRIPTION OF SYMBOLS 1 Propeller shaft 2 Hollow shaft 10, 100, 200 Dynamic damper 20 Outer pipe 30 Weight 40 Elastic body 50 Rubber layer 60 Rubber compression means 70 Diameter expansion part 80 Projection part

Claims (5)

In a dynamic damper having an outer pipe, a weight disposed inside the outer pipe, an elastic body interposed between the outer pipe and the weight, and a rubber layer attached to the outer peripheral surface of the outer pipe,
Rubber compression means is provided at both ends of the rubber layer, and the rubber compression means raises the compression rate at both ends of the rubber layer over the compression rate at the other part of the rubber layer when the dynamic damper is press-fitted into the hollow shaft. Dynamic damper characterized by being a thing.   2. The dynamic according to claim 1, wherein the rubber compression means includes a diameter-expanded portion in which a diameter of an outer peripheral surface of the outer pipe, to which a rubber layer is attached at both ends of the outer pipe, is increased outward in the axial direction. damper.   The dynamic damper according to claim 1, wherein the rubber compressing means includes a protruding portion in which an outer diameter of both end portions of the rubber layer is protruded from an outer diameter of another portion of the rubber layer.   The rubber compression means comprises a diameter-expanded portion having an outer peripheral surface of the outer pipe to which a rubber layer is attached at one end portion of the outer pipe, and is expanded toward the outer side in the axial direction. 2. The dynamic damper according to claim 1, wherein the dynamic damper is composed of a protruding portion in which the outer diameter of the other end portion of the rubber layer located is protruded from the outer diameter of the other portion of the rubber layer.   A propeller shaft in which the dynamic damper according to any one of claims 1 to 4 is press-fitted into a hollow shaft and fixedly arranged.

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